Add a binary that uses a Postgres backend

Building of this binary is controlled with features, allowing downstream
users to build just the SQLite version and not be concerned with the
tokio-postgres dependency tree (which includes links to OpenSSL and
other details). The Postgres version is disabled by default.

This does not change the binary name for the SQLite build, just to avoid
confusion for people upgrading to the new version.

server/src/lib.rs

@@ -1,91 +1,5 @@
 #![deny(clippy::all)]
 
-mod api;
-
-use actix_web::{get, middleware, web, Responder};
-use api::{api_scope, ServerState};
-use std::{collections::HashSet, sync::Arc};
-use taskchampion_sync_server_core::{Server, ServerConfig, Storage};
-use uuid::Uuid;
-
-#[get("/")]
-async fn index() -> impl Responder {
-    format!("TaskChampion sync server v{}", env!("CARGO_PKG_VERSION"))
-}
-
-/// A Server represents a sync server.
-#[derive(Clone)]
-pub struct WebServer {
-    server_state: Arc<ServerState>,
-}
-
-/// Configuration for WebServer (as distinct from [`ServerConfig`]).
-pub struct WebConfig {
-    pub client_id_allowlist: Option<HashSet<Uuid>>,
-    pub create_clients: bool,
-}
-
-impl Default for WebConfig {
-    fn default() -> Self {
-        Self {
-            client_id_allowlist: Default::default(),
-            create_clients: true,
-        }
-    }
-}
-
-impl WebServer {
-    /// Create a new sync server with the given storage implementation.
-    pub fn new<ST: Storage + 'static>(
-        config: ServerConfig,
-        web_config: WebConfig,
-        storage: ST,
-    ) -> Self {
-        Self {
-            server_state: Arc::new(ServerState {
-                server: Server::new(config, storage),
-                web_config,
-            }),
-        }
-    }
-
-    /// Get an Actix-web service for this server.
-    pub fn config(&self, cfg: &mut web::ServiceConfig) {
-        cfg.service(
-            web::scope("")
-                .app_data(web::Data::new(self.server_state.clone()))
-                .wrap(
-                    middleware::DefaultHeaders::new().add(("Cache-Control", "no-store, max-age=0")),
-                )
-                .service(index)
-                .service(api_scope()),
-        );
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-    use actix_web::{test, App};
-    use pretty_assertions::assert_eq;
-    use taskchampion_sync_server_core::InMemoryStorage;
-
-    #[actix_rt::test]
-    async fn test_cache_control() {
-        let server = WebServer::new(
-            ServerConfig::default(),
-            WebConfig::default(),
-            InMemoryStorage::new(),
-        );
-        let app = App::new().configure(|sc| server.config(sc));
-        let app = test::init_service(app).await;
-
-        let req = test::TestRequest::get().uri("/").to_request();
-        let resp = test::call_service(&app, req).await;
-        assert!(resp.status().is_success());
-        assert_eq!(
-            resp.headers().get("Cache-Control").unwrap(),
-            &"no-store, max-age=0".to_string()
-        )
-    }
-}
+pub mod api;
+pub mod args;
+pub mod web;